Bag forming machine



Jana 1936. D. SCHMIDT BAG- FORMING MACHINE Filed Sept. 4, 1934 5 Sheets-Sheet l ATTORNEYQ 193 D. SCHMIDT 2,927,654

BAG FORMING MACHINE Fil'ed Sept 4, 1.9 5 Sheets-Sheet 2 ,2; m gr W ATTO RN EYS Jan. 14, 1936. D, scHMlDT BAG FORMING MACHINE Filed Sept. 4, 1954 5 Sheets-Sheet 3 75,. 6 .mm E N M m w m A m M p ll W v 2 Jan. 14, 1936. D. SCHMIDT BAG FORMING MACHINE Filed Sept. 4, 1934 5 Sheets-Sheet 4 ATTORNEYS D. SCHMIDT BAG FORMING MACHINE Filed Sept. 4, 1934 5 Sheets-Sheet 5 INVENTOR 5 ATTORNEYS Patented Jan. 14, 1936 PATENT OFFICE BAG FORMING MACHINE David Schmidt, Cleveland, Ohio, assignor to The .Dobeckmun Company, Cleveland, Ohio, a corporation of Ohio Application September 4, 1934, Serial No. 742,593 '12 Claims. (01. 93-25) The present invention relates to the art of forming bags, and constitutes improvements upon known types of bag forming machines. The mechanism, here shown and described, relates to mechanisms for making the new form of bags shown and described in my copending application Serial No. 736,208 filed July 20, 1934. As explained more fully in connection with said application, the present inventor has devised certain new and useful improvements in bags or the like,

and methods of making the same, from regenerated cellulose sheeting, or the like. In order that the present invention may be clear, the resultant bags are shown in this application, it being understood that the method and improved article resulting therefrom are described inmore detail and claimed in the above identified application.

In order to illustrate and describe the imso proved mechanism which is operated as an attachment on a well known, or standard form of bag machine, such parts of the machine only are shown as to enable one skilled in the art to 'understand the same. It will also be understood that,

26 while two forms of mechanisms are shown, each of which will form the bag and both of which are generically alike, the invention is not limited to these forms and designs, but may be incorporated in modified or improved form, within the 30 scope. of the invention. 7 Y

The improvements are shown as incorporated in a bag forming machine of that type in which the stock or material is formed into a tube over a mandrel or former, the forward end of the'bag 35 cut oii and then spread by gripper fingers which seize the upper panel or ply of the tube and draw it backwardly over the tube, thus opening up the mouth of the bag into substantially diamond shape. The closure is then formed by folding the 0 diamond-shaped mouth transversely to get the proper seal and closure, the flaps having adhesive applied at the proper points.

This type of bag forming machine is well known, but, as explained in my former applica- 45 tion, the overlapping areas of the flaps at the folded closure do not afiord a suflicient area for the application of the adhesive, so that a firm closure is provided with a stock such as described. To increase the sealing area, cuts which define 50 wings are made in the stock close to the mouth of the tube. These wings, being separated from the main body of the tube, do not partake of the spreading movement. but stand out from the stock, thereby affording increased areas on which 55 the adhesive may be applied.

In the drawings in which the improved mechanism is shown in such detail to enable one skilled in the art to understand the same:

Fig. 1 is a front elevation of an attachment for a bag forming machine embodying the invention; 5

Fig. 2 is a side elevation and partial section thereof on the line 2-2 of Fig. 1;

Fig. 3 is a detail section on the line 3-3 of 2;

Fig. 4 is a longitudinal vertical section through 0 the cutting mechanism;

Fig.5 is a horizontal section on the line 5-5 of Fig. 6;

Fig. 6 is a section on the line 6--6 of Fig. 5;

Fig. 6a. is a perspective view of a cutter blade; 15

Fig. 7 is, a view showing the tubed stock at the end of the cutting operation;

Fig. 8 is a view showing the bag mouth in its spread condition, preparatory to the folding and sealing;

Fig. 9 is a view showing a modified form of the invention; I

Fig. 10 is a section thereof; and

Fig. 11 is a view of the product secured by the mechanism shown in Figs. 9 and 10.

Referring to the form of ag shown in Figs. 7 and 8, which is made by t e mechanism shown, the tube of stock which is ormed over the mandrel is indicated at i, being provided with the longitudinal seam 2. The end of the tube is cut off in forming the bags along the line 3, and at substantially the same time the cuts 4 and 4a are made therein defining the wings 5 and 5a, which give the increased area for the sealing operation. The cuts, being spaced inwardly of the end of the tube, leave the two webs or ribbons 6 and 6a which connect the center portion of the tube with the side edge portions. In this form the wings and ribbons are duplicated on the upper and lower sides or panels of the tube. When the bag moutliis opened in the diamond form characteristic of this method of bag forming, the wings 5 and 5a stand outwardly from the stock, not taking part in the spreading operation but projecting outwardly to give the increase in area over which the adhesive may be applied.

In the operation of the machine, the tube l is formed anddrawn forwardly over the mandrel or former ID, the forward end of which rests, through the tube, upon an anvil II, the upper face of which is provided with a rubber cushion I2, held in place by clamp l3. The upper forward end of the anvil is formed as a cutting edge with which the knife l5 cooperates to cut oil the stock into the proper bag lengths. The mechu anism for operating the knife is not shown as this is well known; it may be stated, however, that the forward movement of the stock is arrested momentarily at the time of cutting and to permit the bag mouth to be spread into the diamond form.

The forward end of the former I0 is cut away as shown by the dotted lines I6 (Fig. 5) along which line the diamond shaped spread is formed. The former is notched at the points I! where the die, to be described, crosses the edge of the former.

A pair of accurately moving gripper fingers l8 are arranged at the end of the former and move in, during the operation of the machine, seizing the center of the top panel and drawing it backwardly to form the diamond spread at the bag mouth. The two positions of these grippers are,

the tube is the plate 20, which is supported, at the rear, on a transverse bar 2|, its forward edge 22 lying closely over the tube and extending transversely across the same to form the square abutment for the spreading operation.

Lo'cated over the anvil is the vertically movable cutter head 25, to the under surface of which is secured the plate 26, carrying a block 21, in which the angular steel cutting blade or die 28 is secured. The cutter blade, a perspective view of which is shovm in Fig. 6a is generally U-shaped with two projecting cutter portions 29, which enter the stock to form the cuts Q, the cuts extending between the points X and Y in Fig. 5. It will be appreciated that the shape of this cutter blade 5 and 50., be formed. A block of rubber 2911 surrounds the die and operates in conjunction with the cushion B2 to grip the stock while thedies form the cuts therein.

To the cutter head is attached a guide pin 30, which is slidably received in a sleeve 3| formed as a part of a bracket 32, which is attached to the frame of the machine 33. The upper end of the pin is provided with opposed grooves 34 in which are received keys 35, which maintain the knife in its proper position.

The cutter head is actuated by means of a link 38, pivoted at its lower end to a pin 39 on the cutter head, and connected at its upper end to a crank 40 on the rock shaft 4|, which is mounted in'the upper end of the bracket. On the shaft is located the gear 43 which meshes with and is driven by the gear segment 44, carried on a rocking arm 45. The latter is-actuated from the drive of the machine by the adjustable rod 46 and spring 41, so that the die is caused to enter the stock during the moment when it pauses for the actuation of the knife [5.

The operation of the mechanism will be apparent from the description which has been given. As the stock is cut by the knife l5, the cutter head is lowered and the wings 5 and 5a are formed therein immediately in the rear of the forward end of the tube. The mouth is Opened by the tongue l9, and the grippers l8 seize the center of the upper panel between the cuts and spread the mouth of the bag to diamond form. This operation is shown in Fig. 4 and the completely spread bag mouth in Fig. 8. After the bag mouth is formed as shown, the tube of stock is advanced to the next cutting point; the bag is severed and goes on through the adhesive applying and folding operations, all of which are standard and well known.

A modified form of mechanism for accomplishing a similar purpose is shown in Figs. 9 and 10; Fig. 11 showing the resultant product. It is not necessary to out both the upper and lower panels to secure the beneficial results desired, as an increase in sealing area may be secured with wings 55 and 55a on one panel only.

In this form of the invention the cutting or slitting is performed in the lower panel only, and this is accomplished by redesigning the forward end of the former 56 so that it is provided with the two angular extensions 51 and 51a. These extensions are sharpened at the points and along the edges so that, as the upper panel is drawn backwardly by the fingers I8, as shown in Fig. 10, the points puncture the stock and it is torn along the lines indicated to form the wings. simple form. of apparatus and may be used, if the form of the bag shown in Fig. 11, is to be employed.

It will be apparent that the invention is capable of embodiment in other forms, and that the illustration and description are merely for the purpose of explaining the invention to those skilled in this art. The invention may be incorporated in a machine operating upon a continuously mov-,

ing stock. A

What is claimed is: 1. The combination in a bag forming machine of meansfor severing a tubular stock transversely, a cutter operating upon the stock at the rear of the transverse cut, and formed to cut longitudinally and transversely of the stock to form wings on opposite sides of the center line thereof, and movable gripping means adapted to seize the upper panel of the stock and move it rearwardly toform a. diamond fold.

2. The combination in a bag forming machine of means for severing a tubular stock transversely, a cutter head carrying a die movable toward the stock to cut longitudinally and transversely thereof to form wings therein on opposite sides of the center line, and grippers adapted to seize the center portion of the upper panel between the wings, and move it backwardly to form a diamond fold.

3. The combination in a bag forming machine of. means for severing a tubular stock transversely, a cutter head carrying a double wing-forming die adapted to cut the stock longitudinally and transversely thereof, said head being movable to cause the die to enter the stock, and grippers adapted to seize the center portion of the upper panel between the wings, and move it backwardly to form a diamond fold.

4. The combination in a bag forming machine of means for severing a tubular stock transversely, a cutter head carrying a wing-forming die adapted to cut the stock longitudinally and transversely thereof, said head being movable to cause the die to enter the stock rearwardly of the severing point to form wings therein, and means to seize the upper panel and move it backwardly to spread the mouth of the stock in diamond form. 5. The combination with a former over which This is a the former terminating in oblique lines, means grippers to move tubular stock is conducted, of means for cutting of! the end of the stock, a cutting device adapted to cut the stock longitudinally and transversely thereof to form wings therein rearwardly of the cutting point, and grippers adapted to seize the center portion of the upper panel and move it backwardly to form the diamond fold.

6. The combination with a former over which tubular stock is conducted, of means at the end of the former for severing the stock transversely, i

and a cutter located rearwardly oi the severing point, and adapted to cut the stock longitudinally and transversely thereof to iorm'wings thereon, and means to open the mouth of the tube in diamond form.

7. The combination with a former over which tubular stock is conducted, the former terminating in oblique lines, means to sever the stock transversely beyond the former, grippers adapted to move the upper panel rearwardly over the end of the former to make a diamond fold, and cutters located outwardly of the former a-rearwardly of the severing point to form wings in the stock.

8. The combination with a former over which tubular stock is conducted, the forward end of the former terminating in oblique lines, means to sever the stool; transversely beyond the former, grippers adapted to move the upper panel rearwardly over the end of the former to make a diamond fold, and cutting projections on the former adapted to enter the lower panel and form wings therein.

9. The combination with a former over which tubular stools is conducted, the forward end 01? the forward end of to sever the stock transversely, the upper panel rearwardly over the ijormer to make a diamond iold therein, and means cooperating with the grippers to cut wings from the stock which stand outwardly from the diamond fold.

10. The combination with a formerover which tubular stock. is conducted, the forward end of the former terminating in oblique lines, means to sever the stock transversely, grippers to move the upper panel rearwardly over the former to make a diamond fold therein, and means associated with the mechanism to cut wings from the stock which stand outwardly from the diamond fold.

ill. The combination with a former over which tubular stock is conducted, the forward end of the former terminating on oblique lines, means to sever the stock transversely beyond the former, grippers to seize thecenter of the upper panel and to move it backwardly to form a diamond fold, and means associated with the foregoing mechanism to cut wings in the stool: laterally of the end of the former.

' 12. The combination with a former over which tubular stock is conducted, the forward end of the former terminating on oblique lines, means to sever the stock transversely beyond the former,

grippers to seize the center of the upper panel and to move it backwardly to form a diamond fold, and means associated with the foregoing mechanism to cut wings in the lower panel laterally of the end or the former.

- DAVID SC 

